KINETIC MODELLING OF CHEMICAL AND ENZYMATIC PROCESSES WITH LIGNOCELLULOSIC FIBER MATERIALS

Authors

  • Greta Radeva University of Chemical Technology and Metallurgy
  • Ivo Valchev University of Chemical Technology and Metallurgy
  • Stoyko Petrin University of Chemical Technology and Metallurgy
  • Ivaylo Gavrilov University of Chemical Technology and Metallurgy

DOI:

https://doi.org/10.59957/jctm.v61.i6.2026.10

Keywords:

kinetic modelling, lignocellulosic materials, process optimization

Abstract

Optimization of pulping, bleaching and biorefining processes requires a good understanding of reaction kinetics.
The kinetics of the processes are described by kinetic equations valid for processes taking place at heterogeneous surfaces. The investigation clarifies the influence of operating parameters on the effectiveness of various processes with lignocellulosic fibre materials. The kinetics of oxygen delignification are described by a modified form of the topochemical kinetic equation, while the same kinetic mechanism was found to govern both chlorine dioxide bleaching and xylanase-assisted bleaching. The kinetics of hydrolysis with cellulase complexes is described by an exponential kinetic equation.
Common kinetic expressions were developed to describe the combined effects of reaction time, enzyme concentration, temperature, and other relevant operating parameters on process efficiency.

References

I. Valchev, Chemical Pulp Bleaching, in: V.I. Popa (Ed.), Pulp Production and Processing: From Papermaking to High-Tech Products, Smithers Rapra Technology Ltd, Shawbury, 2013, 71-118.

S. Nenkova, I. Valchev, G. Simeonova, Possibilities for increasing the effectiveness of oxygen delignification of hardwood kraft pulp, J. Pulp Pap. Sci., 29, 10, 2003, 324-327.

L. Olm, A. Teder, The kinetics of oxygen bleaching, Tappi J., 62, 12, 1979, 43-46.

I. Valchev, E. Valcheva, E. Christova, Kinetics of oxygen delignification of hardwood kraft pulp, Cellul. Chem. Technol., 33, 3-4, 1999, 303-310.

M.J. Joncourt, P. Froment, D. Lachenal, C. Chirat, Reduction of AOX formation during chlorine dioxide bleaching, Tappi J., 83, 1, 2000, 144-148.

M.J.M.C. Barroca, P.J.T.S. Marques, I.M. Seco, J.A.A.M. Castro, Selectivity studies of oxygen and chlorine dioxide in the pre-delignification stages of a hardwood pulp bleaching plant, Ind. Eng. Chem. Res., 40, 24, 2001, 5680-5685.

B.N. Brogdon, L.A. Lucia, New insights into lignin modification during chlorine dioxide bleaching sequences (III): The impact of modifications in the (EO) versus E stage on the D1 stage, J. Wood Chem. Technol., 25, 3, 2005, 133-147.

I. Valchev, G. Simeonova, S. Nenkova, J. Gaidarov, Evolution in hardwood kraft pulp bleaching: A comparison of options, Cellul. Chem. Technol., 39, 1-2, 2005, 105-114.

I. Valchev, G. Simeonova, S. Nenkova, E. Valcheva, J. Gaidarov, Evolution of the ECF hardwood bleaching for better chemical efficiency, Balkan Pulp Pap. News, 5, 12, 2004, 25.

I. Valchev, I. Dimitrov, E. Valcheva, S. Veleva, Kinetics of pressured peroxide bleaching of hardwood pulp. Part II. Effect of enzyme treatment on pulp, Cellul. Chem. Technol., 38, 1-2, 2004, 67-77.

L. Viikari, A. Kantelinen, J. Sundquist, M. Linko, Xylanases in bleaching: From an idea to the industry, FEMS Microbiol. Rev., 13, 2-3, 1994, 335-350.

C. Deneault, C. Leduc, J.L. Valade, The use of xylanases in kraft pulp bleaching: A review, Tappi J., 77, 6, 1994, 125-131.

I. Valchev, L. Yotova, E. Valcheva, Kinetics of xylanase treatment of hardwood pulp, Bioresour. Technol., 65, 1-2, 1998, 57-60.

E. Valcheva, S. Veleva, I. Valchev, I. Dimitrov, Kinetic model of xylanase action on kraft pulp, React. Kinet. Catal. Lett., 71, 2, 2000, 231-238.

E. Valcheva, I. Valchev, L. Yotova, Kinetics of enzyme action of Cartazyme NS-10 prior to bleaching of kraft pulp, Biochem. Eng. J., 7, 3, 2001, 223-226.

I. Dimitrov, I. Valchev, E. Valcheva, Topochemical kinetics of xylanase action on kraft pulp, Biocatal. Biotransform., 23, 1, 2005, 33-36.

F. Alfani, A. Gallifuoco, A. Saporosi, A. Spera, M. Cantarella, Comparison of SHF and SSF processes for the bioconversion of steam-exploded wheat straw, J. Ind. Microbiol. Biotechnol., 25, 4, 2000, 184-192.

F. Carrillo, M.J. Lis, X. Colom, M. López-Mesas, J. Valldeperas, Effect of alkali pretreatment on cellulase hydrolysis of wheat straw: Kinetic study, Process Biochem., 40, 10, 2005, 3360-3364.

J. Chrastil, Enzymic product formation curves with the normal or diffusion limited reaction mechanism and in the presence of substrate receptors, Int. J. Biochem., 20, 7, 1988, 683-693.

J. Chrastil, Determination of the first order consecutive reaction rate constants from final product, Comput. Chem., 12, 4, 1988, 289-292.

J. Chrastil, J.T. Wilson, The effect of chemical and physiological factors on the kinetics for product formation as it relates to enzyme activity and concentration, reaction time and to substrate adsorption and affinity, Int. J. Biochem., 14, 1, 1982, 1-17.

G.L. Miller, Use of dinitrosalicylic acid reagent for determination of reducing sugar, Anal. Chem., 31, 3, 1959, 426-428.

G. Radeva, I. Valchev, S. Petrin, E. Valcheva, P. Tsekova, Comparative kinetic analysis of enzyme hydrolysis of steam-exploded wheat straw, Cellul. Chem. Technol., 46, 1-2, 2012, 61-67.

G. Radeva, I. Valchev, S. Petrin, E. Valcheva, P. Tsekova, Kinetic model of enzymatic hydrolysis of steam-exploded wheat straw, Carbohydr. Polym., 87, 2, 2012, 1280-1285.

I. Valchev, G. Simeonova, Kinetic models for investigation and control of the bleaching processes, Proceedings of the 2005 International Pulp Bleaching Conference, Stockholm, Sweden, 14-16 June 2005, 272-274.

I. Valchev, P. Tsekova, Xylanase post-treatment as a progress in bleaching processes, Appita J., 63, 1, 2010, 53-57.

G. Radeva, I. Valchev, E. Valcheva, Thermodynamics and kinetics of the adsorption of cellulase on bleached and unbleached pulp, in: L. Wang, S. Kuang, Q. Hou, C. Cao, C. Si, H. Zhang (Eds.), Proceedings of the 16th International Symposium on Wood, Fiber and Pulping Chemistry, Tianjin, China, 2011, 516-521.

S. Petrin, N. Yavorov, P. Tzvetkov, I. Valchev, G. Radeva, Kinetic aspects of enzyme hydrolysis of cellulose fibre material, Bulg. Chem. Commun., 47, Special Issue A, 2015, 30-33.

G. Radeva, I. Valchev, S. Petrin, E. Valcheva, P. Tsekova, Kinetic study of the enzyme conversion of steam-exploded Paulownia tomentosa to glucose, BioResources, 7, 1, 2012, 412-421.

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Published

2026-11-01

Issue

Vol. 61 No. 6 (2026)

Section

Articles

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